


The Devil Inside You

by SapphireSmoke



Category: Lightning Returns: Final Fantasy XIII
Genre: Explicit Sexual Content, F/F, Farroncest - Freeform, Guilt, Lesbian Sex, Masturbation, Mindfuck, Self-Acceptance, Self-Hatred, Selfcest, Sexual Fantasy, Shame, Sibling Incest
Language: English
Status: Completed
Published: 2018-08-02
Updated: 2018-08-02
Packaged: 2019-06-20 17:53:12
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,413
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15539742
Author URL: https://archiveofourown.org/users/SapphireSmoke/pseuds/SapphireSmoke
Summary: It had always been hard for Lightning to accept the worst parts of herself. Unfortunately, Lumina knew this better than most.





	The Devil Inside You

**Author's Note:**

> **Beta:** [Aifrit](https://archiveofourown.org/users/Aifrit/pseuds/Aifrit)  
>  **A/N:** Blame everyone on that damn Farroncest discord server for this, lmao. You know who you are. Also, this fic gives a whole new meaning to the term ‘self-love’. Ha.  
> 

 

A disembodied giggle echoed through the chaos as Lightning stood in the center of nothingness, her body poised and ready for the fight she knew was coming, as there was only one person who ever brought her to this place. The sound of the demon’s laugh felt as though it were wrapping around her, seeping into her, and hollowing her out as it left Lightning cold and alone. The smoke began to billow around her then, and the form of a young girl and appeared before her eyes.

Lumina grinned wide, her hands clasped behind her back as she rolled back onto her heels. She wanted to look innocent, to be _cute_. Lightning knew that she was neither. “Miss me…?”

“Like a cold sore,” Lightning deadpanned, because that’s what Lumina was to her, an _infection._ She was just another part of this diseased world that only sought to cause misery and pain, and Lightning was having none of it. She scoffed, tired of this charade. “I’m not in the mood for your _games_ right now, Lumina. I told you to stop bringing me here. Whatever you’re trying to accomplish with this little stunt of yours, it won’t work. You can’t keep me from saving the world, from saving _Serah_.”

“ _Serah, Serah…”_ Lumina mocked, her eyes growing harder as she looked up at the woman in front of her. The smoke around her darkened to an inky black, making the air feel thick and heavy and _wrong._ “Is she all you think about? Serah, your obsession. Your _secret._ Do you really think I don’t know?” Lumina laughed then and it was cruel, so unlike the girly sound that used to make its way past her lips as she skipped around, causing the world to unravel beneath her feet.

It unnerved Lightning in a way she would never admit out loud. “You know _nothing_ about me.”

Lumina’s form shifted and flickered, an image of Serah replacing the trickster for a brief moment. It was gone as soon as it came though, yet when Lumina spoke, it was not with her own voice. “Why haven’t you come for me yet, Claire? I thought you loved me. I thought I was your everything. Why am I all alone…?”

“Stop it!” Lightning demanded, a surge of unexpected emotion rising within her as her hand wrapped around one of Lumina’s arms, her nails digging into her flesh. “Don’t you _dare_ —”

“I’m cold, Lightning. It’s so cold here without you…”

“I said _stop!”_ Lightning bellowed, pushing Lumina away from her with all of her force. The girl went sprawling to the floor, but it didn’t seem to faze her. Instead, she merely laughed, her voice returning to normal. Lightning’s breathing was heavy and uneven, a tightness constricting her chest so badly it felt as though it may very well crush her.

Why could she feel it? Where were they, _really?_

She was supposed to be empty and yet when Lumina was near, it made Lightning feel close to being whole. She didn’t like it. She didn’t _want_ it. Emotions clouded her judgement; made her irrational and unpredictable, and that was why Bhunivelze stripped her of them. Why then, in this place, with this girl, was she able to feel the pain of Serah’s absence?

 _“_ What _are_ you _?”_ Lightning demanded, needing an answer to this madness. Everything about Lumina felt so familiar and yet so entirely separate that it pushed and pulled at her in a way that left her dizzy and breathless. It was why she couldn’t stand it when the girl was around. It was why she felt the need to reject her at every turn, because something about her just wasn’t right.

“You know what I am,” Lumina insisted with a cheshire grin before the chaos enveloped her, obscuring her from view. Lightning was about to stomp over to her and _demand_ a real answer, but suddenly she felt a breath against the back of her neck, and she stiffened as familiar hands slid down her arms, her back.

The Savior did not move, as she was not about to admit that the child was beginning to unnerve her. Lumina could play her _games_ all she wished, but that did not mean that Lightning had to participate in them.

“Why haven’t you told her, Lightning?” Lumina goaded softly, her voice sounding far too sultry to be coming from someone her age. If she even _was_ the age she appeared – Lightning was beginning to doubt it. Nothing about Lumina seemed right, and there was a part of Lightning that wanted to dissect it, dissect _her,_ and find out why. “Did you really think locking it up in the dark recesses of your mind would make it go away…?”

Lightning suddenly felt sick. If Lumina was implying what she thought she was, then all of her desire to stay calm, to stay stoic and uncaring during the imp’s stupid goading, was about to fly right out the window. She couldn’t. Not about _that_.

Her jaw clenched. “You don’t know what you’re talking about.”

Lumina giggled softly, and the chaos enveloped the girl’s form in order to bring Lumina in front of her once more. Yet instead of the demon’s image materializing in a swirl of inky darkness, Lightning noticeably started as she found herself face to face with _herself._ The image flickered; once, twice, and then it solidified on a completely _bare_ version of the woman standing in front of it.

A hand was between fake Lightning’s thighs, a name being breathed out between parted lips. _“Serah…”_

It echoed. Taunted. Destroyed.

Something angry and feral ripped from Lightning’s throat as all this fear, all this _shame_ hit her without any remorse. She launched her body at the image, but instead of hitting something solid, it flickered and died out, another laugh echoing through the darkness as Lightning’s body hit the floor. The Savior half-turned from her place on the ground, her hair falling in front of her eyes as she set her sights on the figure that was now behind her.

She wanted to rip her _apart_.

“Now, now, don’t get pouty,” Lumina chided, wagging her finger at her. “You forget I’m here to help!”

“All you’ve done is _fuck_ with my head,” Lightning ground out as she pushed herself into a standing position. Her blood pounded so hard in her ears that she could barely hear anything other than the sound of her own voice, but it didn’t matter, because she didn’t want to listen to anything Lumina was going to tell her anyway. Whatever she was, she didn’t want her _near_ her; not if she could see into her mind like that. That was dangerous. That was… that was _devastating._ “I don’t want your help. I want you _gone._ ”

“Then _finally_ we have something in common, don’t you see?” Lumina responded with fake joy, clapping her hands together as she bounced on the balls of her feet. The sight took Lightning aback for a moment, as that wasn’t what she was expecting at all. However as soon as that charade began it was over now, Lumina growing angry as she crossed the distance between them, fire in her eyes. “I don’t want to exist anymore than you want me to, _sis_. I used to be a part of something, I used to be whole until I was cast out, and you— _you_ with your selfishness and your weak mind, failed me just as you have everyone else! Hope, Snow, Fang, Vanille, Sazh, _Serah…”_

“Shut _up—!”_ Lightning warned, not wanting to be reminded of her failures, even if she understood her blame in all of them, except for Lumina. How had she wronged her? Who _was_ she, really? Was that why the girl was bringing her to this place, to punish her for failing her in some way? Is that why she taunted her, why she picked apart her mind and laid her weaknesses out for all the world to see?

 _“Why don’t you love me?!”_ Lumina demanded, her hands finding Lightning’s biceps as she shook her, desperation in her eyes. She looked lost, broken, and the shift in her behavior and tone nearly knocked the wind out of Lightning as she stared down at something so frightening in its familiarity. “Why do you have to love her more than _me?!”_

“Wha—?” Lightning tried, feeling as though the world was spinning beneath her feet. Nothing about this was making any sense, and yet there was a part of her that ached to assure Lumina that she mattered, that she was _loved_. But how? _Why?_ Lightning didn’t know her, did she? This was all madness, just another _game_ of hers, wasn’t it…?

And then suddenly Lumina was not Lumina anymore but _Serah,_ this image holding much longer than the last yet her voice seemed broken, fractured. It echoed with Lumina’s as the girl in front of her pushed and pulled at Lightning, desperation in her tone. “You broke yourself for me, Claire! For _this,”_ she insisted, her words becoming breathy as the girl’s hand was now cupping her cheek, lips pressing against hers. For a moment, Lightning forgot the truth and immersed herself in the lie as Lumina spoon-fed her the one thing that could make nothing else matter to her.

But it didn’t last long.

Lightning’s brain eventually caught up with the situation and she tore her face away from the lie, demanding, “Stop it! Stop _looking_ like her!” It was bad enough that Lumina could make herself look like Serah, but it was another thing entirely that she was catering to her perverted fantasies for God only knew what reason.

Except God _didn’t_ know, did he? That was why Lumina brought her here, to this place; it was the one place Bhunivelze couldn’t reach.

Lumina’s form flickered, her voice shifting back into her own even though she continued to be Serah every moment or two. It was driving Lightning mental, as she no longer knew what was real. Perhaps none of this was. “You’re scared,” Lumina accused, her voice coming from lips that Lightning now knew far too intimately. “You threw that part of you away because you want to believe that she doesn’t love you back. But she does. You know she does. _You_ just think it’s sick – the way you both love one another. You want to protect yourself, protect _her_ most of all _,_ but all you ever do is cause you both pain.”

Lightning wanted to throw up. It was true; it was too much truth and Lumina couldn’t—she _shouldn’t_ know it. But she knew it all too well, and Lightning began to fear the reason why, and so she denied her time and time again. “You don’t know _anything—"_

“It _hurts,_ Claire,” Lumina insisted, no longer glitching into someone she should not be. However, despite her image and her voice being her own now, her words were all Serah, and Lightning knew it. They twisted in her gut, reminding her of the conversation she and Serah had almost had all those years ago in Bodhum before Lightning had shut her sister down for Serah’s own good, because they _couldn’t._ “Why don’t you accept us?”

 _“Because I won’t be the one to fuck you up!”_ Lightning shouted, all control over her emotions disappearing into nothing as she was confronted by the one reality she didn’t want to face. Her cheeks were wet, but Lightning hadn’t realized she had started crying. She just looked at Lumina helplessly, needing her to understand why she did what she did.

“No, of course you won’t be,” Lumina breathed softly, sadly, an honest look of compassion in her eyes as she gently placed her palm on Lightning’s cheek. She looked devastated, and it tore Lightning to pieces. “Because you’d rather fuck yourself up instead.”

And it was then that Lightning realized what she was.

She was something she could never find within her to accept. She was all the ugliness, all the darkness that lay inside of her – a manifestation of her own guilt and sin. Lightning had denied that part of her so much that it fled from her heart to lay waste to her mind, in a place where only Lightning herself could see. She was suffocating the life out of Lumina, out of _herself,_ and Claire Farron – _all_ of Claire Farron –  only wanted to survive.

“I’m sorry…” Lightning choked out, the words getting stuck in the back of her throat as she looked at the part of herself she had always wished to forget. Another tear slipped down her cheek as she lay her hand delicately on top of Lumina’s that resided on her cheek, suddenly seeing the girl in a whole new light.

“Why don’t you love me…?” Lumina sighed, suddenly seeming so much smaller than the girl that was taunting her not long ago. It was like she was a different person but that was the thing, wasn’t it? She _wasn’t._ Neither of them were different, as they were one and the same.

“Because there’s something wrong with the way you love,” Lightning breathed regrettably. That wasn’t the only reason, of course, but it was a large part of it. But all her impulsive, rash, emotional decision making went out the window along with Lumina, and that was probably why the girl did what she did next.

“Maybe,” she admitted, which was more than Lightning was expecting. But Lumina wasn’t done. “But it’s okay, you know, to wish for something sometimes. It’s okay to want. It’s okay to pretend…”

Lumina’s form shifted once more then, a familiar pair of lips gently covering the Savior’s as a delicate hand weaved through her hair, bringing her closer. Lightning inhaled a sharp breath, but did not immediately pull away from the figure that now looked like her sister. Now that she knew what Lumina was, the lie didn’t feel… as _hostile_ as it had before.

“You break apart when you bottle it all up inside you, Claire,” Lumina-as-Serah breathed against the other woman’s lips before she pulled away just enough to search her eyes. “It’s okay if you want to protect me out _there_ , but in here… what’s the harm, right? It’s just a fantasy, it won’t hurt anyone…”

“Lumina…” Lightning warned gently, as a part of her still felt like she was being manipulated. But could someone really manipulate _themselves?_ This wasn’t even real, just some twisted trip through her own chaos-clouded heart. Lightning probably wasn’t even awake, so wouldn’t it be foolish not to indulge in a dream?

No, she shouldn’t be justifying this—

“You need to let yourself _feel_ it, Claire,” Lumina insisted, the words falling from Serah’s mouth making them seem all the more appealing, all the more _convincing._ “You can’t lock this part of you up forever. And maybe… maybe if you let yourself love _her,_ even for a minute, then you… then maybe you’d love _me.”_

Lightning wanted to tell her that it didn’t work like that, but she didn’t get the chance. Lumina’s lips were on hers again, the girl tasting of Serah and sin as this time she kissed her firmer, more insistent. And Maker forgive her, but instead of pushing her away Lightning parted her lips, finally allowing Lumina to be a part of her, even if it was in such a colluded, perverted, and unconventional way as this. But did it matter, really? What this was or wasn’t? No one else was there, no one else would _know,_ and there was a part of Lightning that ached to find the other part of her soul again, to feel _whole_ again.

Even if it just ended up being inside of her own mind.

So Lightning allowed this to happen, whatever _this_ was supposed to be. It felt sexual but at the same time not at all; at times, it merely felt like she was just accepting and acknowledging a part of her that she had denied herself for so long. Sex, emotion, _desire…_ those were all things that Lightning hadn’t felt for a long time now, and now that she was experiencing them again they overwhelmed her to the point that Lightning barely knew what she was doing anymore as she tore at clothing that probably never existed in the first place, feeling a familiar pulse point jump beneath her lips before she bit down, encouraging a deep moan to rip from Lumina’s lips.

~~From her own lips?~~

“Claire,” Lumina breathed, but it was Serah now, Serah who was naked and wanting as her hands grasped for purchase against Lightning’s bare skin, holding her closer to her. Somehow they had found themselves on the ground now, an image of Serah sitting astride Lightning’s lap as she ground herself against her pelvic bone, leaving streaks of desire in her wake. Lightning shuddered at the feeling, her lips finding the skin of her shoulder before her hand snaked between their bodies, entering something that felt far too real to only be a figment of her imagination.

Lightning groaned as she moved within her slick passage, pushing deeper until the image of Serah flickered and disappeared, leaving Lumina atop her with her mouth hung open in pleasure. The reality of the dream didn’t stop Lightning though, didn’t make her see how twisted this had all become as she instead fucked her deeper, watching the girl writhe and moan atop her. Chaos clouds had wrapped around them both, snaking around their forms as it consumed their very beings. Lightning could not see anything else but the girl perched atop her though, Lumina’s eyes boring into hers as she begged her for something Lightning both feared, yet needed so desperately.

“Please,” Lumina breathed, her palms warm against the Savior’s face. “Please, Claire, I want to be loved…”

“You _are,”_ Lightning insisted strongly, because even though it felt wrong when she was awake, here, _now,_ it finally felt okay. It finally felt _normal,_ despite this all being so very far from it. Lumina’s hips pushed deeper into her hand, her insides clenching around her and pulling her deeper, closer. She wanted to be a part of her again and in that moment, Lightning could not find it within herself to deny her anymore.

She wanted to be _whole_ again.

Lumina started to shake, her image becoming unstable as she began to unravel in her hands. She was Serah, she was herself, but then she was an image of _Lightning_ as suddenly the woman atop her was the same height, the same stature, the same _face._ Lightning looked at her mirror image and watched herself come undone, and for the first time in what felt like forever, Lightning realized that she was beautiful.

That she loved herself, despite all of her flaws.

It was both frightening and exhilarating and Lightning hooked her fingers inside of herself, realizing that she was no longer fucking a part of herself, but her whole _being_ as she herself began to shake and writhe, her orgasm washing through her with such intensity that tears began to leak from the corners of her eyes as her hips twitched and blood pounded in her ears. It was both not enough and yet at the same time far too much, and when it was all over Lightning just lay there, breathless and spent as she looked up at the darkness surrounding her, wondering what this made her now.

“He’s using you.”

Lumina’s voice echoed, but for once it didn’t feel like it was outside of her, but inside of her own mind. Lightning closed her eyes, finally allowing herself to focus on the piece of her she had tried for so long to ignore. _Who?_ She almost asked, yet she already knew. Maybe she had always known.

Bhunivelze.

“He seeks to destroy, not rebuild. You need to be _angry_ , Light. You need to feel, you need to _fight_ , or He’ll take her from us. Serah will be gone, Claire. _Serah will be gone._ ”

Something hit Lightning so hard in the chest that the woman gasped hard, feeling everything she had long since denied herself. It felt suffocating, overwhelming, and yet nothing could cripple Lightning enough to keep her from saving her sister. Not herself, not the world, and certainly not _Him._

And so she stood, and was reborn anew.

Lightning Farron, the Savior of the World… and the Slaughterer of Gods.

**THE END**


End file.
